Highly Enantioselective Cyclopropanation in Alcoholic and Aqueous Solvents Catalyzed by Optically Active β-Ketoiminato Cobalt(II) Complex

Abstract

The highly enantioselective cyclopropanation of styrenes and diazoacetates proceeded in alcohol or aqueous alcohol in the presence of the β-ketoiminato cobalt(II) complex. Water and alcohols accelerated the reaction and improved the diastereo- and enantioselectivities. In these media, the α,α-disubstituted styrenes were smoothly cyclopropanated with high enantiomeric excess.